Digital cameras with interchangeable lenses have surged in popularity in recent years. With these digital cameras, when the user looks at a subject through a viewfinder, the optical path is varied by a reflecting mirror. More specifically, light that has passed through the optical system (that is, the subject image) is reflected by a reflecting mirror disposed along the optical path. The reflected light goes through a pentaprism, etc., and is converted into an erected image, then guided to an optical viewfinder. This allows the user to see the subject image that has passed through the optical system by looking into the optical viewfinder. Therefore, the position at which the viewfinder optical path is formed is usually the home position of the reflecting mirror.
On the other hand, when a lens is used for imaging, the reflecting mirror instantly changes its position and is retracted from the imaging optical path, which switches the viewfinder optical path to the imaging optical path, and the reflecting mirror instantly returns to its home position upon completion of the imaging. This system is the same for both conventional silver halide cameras and digital cameras, if they are single lens reflex types.
A feature of a digital camera is that an image is captured while the user looks at a display device (such as a liquid crystal monitor), and the captured image can be checked right after it is captured. However, when a conventional single lens reflex reflecting mirror is used, a liquid crystal monitor cannot be used during imaging. Since imaging cannot be performed by using a liquid crystal monitor, the user has to look through the viewfinder during imaging, so conventional camera systems have been extremely difficult to use, especially for novices who are inexperienced in using digital cameras. There is also a need for functions such as moving picture imaging, rather than just still picture imaging.
In view of this, there has been a proposal for a digital single lens reflex camera with which imaging can be performed while looking at a liquid crystal monitor (see Patent Citation 1, for example).
However, with an interchangeable lens type of digital camera, when an image is captured using a liquid crystal monitor, since the user is farther away from the digital camera than when imaging is performed by looking into a viewfinder as in the past, it is difficult for the user to operate the camera while looking directly at the interchangeable lens. Also, the numerical value that indicates the state of the zoom ring or focus ring is sometimes eliminated in order to make a digital camera smaller. In this case, when the user attempts to change the zoom magnification (focal length) or the object distance (hereinafter also referred to as the subject distance), it is hard to tell which way the operation member of the interchangeable lens should be moved, and this makes the camera more difficult to operate.
In view of this, there has been a proposal for a digital camera in which the direction in which the zoom lever is operated and the zoom position are displayed on a display unit by using text or a character pattern (see Patent Citation 2, for example).
Also, there has been a proposal for a digital camera with which the operation direction of the focus ring can be selected as desired (see Patent Citation 3, for example).
Patent Citation 1: Japanese Laid-Open Patent Application 2001-125173
Patent Citation 2: Japanese Laid-Open Patent Application H5-153456
Patent Citation 3: Japanese Laid-Open Patent Application H5-181047